their life cycle) is for offshore life stages and does not 

 adequately describe estuarine distributions (Darnell et 

 al. 1983. NOAA 1988). 



An objective of this project is to map species distribu- 

 tions from the head-of-tide in estuaries to the far 

 reaches of the continental shelf. 



Only a few comprehensive sampling programs (e.g., 

 states of Louisiana and Texas) collect fishes and 

 invertebrates with identical methods across groups of 

 estuaries within a region (Barrett et al. 1978, 

 Hammerschmidt and McEachron 1986). Therefore, 

 most existing estuarine fisheries data cannot be com- 

 pared anxjng estuaries because of the variable sam- 

 pling strategies. In addition, existing research pro- 

 grams do not focus on how groups of estuaries may be 

 important for regional fishery management, and few 

 compile information for species having little or no 

 economic value. 



Because life stages of many species use both estua- 

 rine and marine habitats, information on distribution, 

 abundance, temporal utilization, and life history char- 

 acteristics are needed to understand the coupling of 

 estuarine, nearshore, and offshore habitats. To date, a 

 national, comprehensive, and consistent data base of 

 this type does not exist. Consequently, there is a need 

 to develop a program that integrates fragments of 

 information on marine and estuarine species and their 

 associated habitats into a useful, comprehensive, and 

 consistent format. The ELMR program was designed 

 to help fulfill this need by developing a uniform nation- 

 wide data base on selected estuarine species. Results 

 will complement NOAA efforts to develop a national 

 estuarine assessment capability (NOAA 1985), iden- 

 tify information gaps, and assess the content and 

 quality of existing estuarine fisheries data. In addition, 

 the ELMR program provides the estuarine distribution 

 data for NOAA's recently initiated East Coast of North 

 America Strategic Assessment project (NOAA 1991). 



National 



Estuarine 



Inventory 



Data 



31 

 Estuaries 



Compile 

 ^ Estuary 

 Information 



Prepare 



Species/Estuary 



Data Sheets 



Data Collection and Organization 



Figure 2 summarizes the major steps taken to collect 

 and organize information on the distribution and abun- 

 dance of fishes and invertebrates in Gulf of Mexico 

 estuaries. The initial steps were selecting the estuaries 

 and the species to be studied. 



Selection of estuaries. Gulf of Mexico estuaries were 

 selected from the National Estuarine Inventory (NEI) 

 Data Atlas-Volume I (NOAA 1985) and NEI Supple- 

 ment 3 (Shirzadetal. 1989). The3l estuaries selected 

 are listed in Table 1 , and their locations shown in Figure 

 3. 



Data on spatial and temporal distributions of species 

 were developed and organized by the tidal fresh (0.0 to 

 0.5 parts per thousand (ppt)), mixing (0.5 to 25.0 ppt), 

 and seawater (>25.0 ppt) zones delineated for each 

 estuary in the NEI. Each salinity zone is represented 

 in 17 of the Gulf of Mexico estuaries, but 14 estuaries 

 are missing at least one zone (Table 1). A representa- 

 tive map and data table for Mobile Bay from the NEI 

 Data Atlas is shown in Appendix 1 . 



Compiling consistent data nationwide limits the amount 

 of information that may be compiled for each species 

 and estuary. Also, it would be time- and cost -prohibitive 

 to map each species by life stage for each estuary 

 (Monaco 1986). The NOAA framework allows for a 

 consistent compilation and organization of available 

 information on the distribution of fishes and inverte- 

 brates in estuaries. 



Outputs 



Peer Review: 

 Data Verification 



Spatial 

 Distribution 



Microcomputer 

 Data Base 



Temporal 

 Distribution 



Relative 

 Abundance 



Figure 2. Major steps to complete the Gulf of Mexico ELMR study. 



Data 

 Reliability 



